Chloroplast DNA restriction site variation and phylogenetic interrelationships of some genera of the Heliantheae sensu lato (Asteraceae)

Phylogenetic interrelationships of 12 genera of the Heliantheae s. lat., as well as two genera of the Anthemideae and Eupatorieae, were assessed by chloroplast DNA restriction site analysis. The 14 investigated species represented Guizotia, Helianthus, Melampodium, Rudbeckia, Sigesbeckia, Tridax , and Verbesina (Heliantheae s. str.), Helenium, Hymenoxys , and Palafoxia (Helenieae), Porophyllum (Tageteae), Coreopsis (Coreopsideae), Pleurocoronis (Eupatorieae), and Anthemis , (Anthemideae). Using 9 enzymes, 39 phylogenetically informative sites were found. Wagner parsimony analysis of the data yielded 10 equally parsimonious cladograms. Well supported relationships displayed by all cladograms included (1) a clade comprising all the genera (Heliantheae s. lat. and Eupatorieae) except Anthemis (Anthemideae), (2) a clade consisting of the genera of the Heliantheae s. str. with Pleurocoronis (Eupatorieae) nested among them, (3) a subclade of the former comprising Pleurocoronis, Guizotia , and Sigesbeckia , and (4) the generic pair of Helenium and Hymenoxys.